Fabric-like material produced with resin or latex foam compositions are well known and many are commercially available. In some instances they have a flocked surface but often they do not. A particularly suitable flocked foamed latex sheet is disclosed in U.S. Pat. No. 4,056,646, issued on Nov. 1, 1977 to P. M. Westfall and H. Mayfield, wherein is described the procedures for producing pliable, soft, foamed latex sheets of good hand and breathability having many uses. However, it has since been discovered that the procedures and compositions discussed in this patent often require a commercially unacceptable period of time for curing of the latex formulation thus detracting somewhat from commercial acceptance for many applications. The instant invention has resolved this problem to a significant extent by the selection of specific foamable mixtures added at critical concentrations to the resin or latex formulation.
Though the use of foamable compositions is known, none heretofore employed have achieved the successes herein attained. In U.S. Pat. No. 3,577,554 issued on May 4, 1971 to D. B. Parrish et al. there are described formulations of carboxyl-containing copolymer latexes reacted with an aziridine to obtain a polymer latex having both aminoester and carboxyl groups. The pH of this polymer latex is then adjusted to greater than 7, it is foamed, applied as a foam and cured to dry and form a frothed sheet. An important aspect of this process is the requirement of a basic pH value.
U.S. Pat. No. 3,491,033 issued on Jan. 20, 1970 to E. R. Dunn teaches the conversion of a foam to a solid cellular material without gelling the wet foam by use of a mixture of foaming agents and mentions that di-sodium N-octadecyl sulfosuccinamate can be used as a component of one of the specific mixtures.
Foam coated composites are disclosed in U.S. Pat. No. 3,607,341 issued on Sept. 21, 1971 to R. E. Goins et al., with the disclosure making reference to the use of salts of aliphatic sulfates or alkaryl sulfates among the useful foaming agents or surfactants.
Synthetic rubber foams based on styrene copolymer latexes are disclosed in U.S. Pat. No. 3,215,647 issued on Nov. 2, 1965 to E. R. Dunn. The patentee shows the separate use of ethoxylated nonylphenols and alkali metal salts of alkyl sulfates at acidic pH values. However, the composition must contain a coreactive material containing at least two substituent groups coreactive with the reactive groups on the latex in order to obtain a good foam.
R. C. Nahta in U.S. Pat. No. 4,198,316 issued on Apr. 15, 1980 discloses the use of mixtures that can contain an alkali metal salt of an alkyl sulfate as foaming agent in conjunction with at least two other components, one being a "dispersant" and the other a "stabilizer." The reference indicates the need of a basic pH value for the foamable mixture.
Nonstable foams are disclosed in U.S. Pat. No. 4,099,913 issued on July 11, 1978 to A. T. Walter, G. M. Bryant and R. L. Readshaw. These foams are produced using a variety of foaming agents, applied to a substrate, and are characterized by a short foam half-life that results in rapid breaking of the foam on contact with the substrate.